1. Field of the Invention
This invention relates to methods for waterproofing or dampproofing various water-penetrable construction materials in which improved, pre-formed, flexible sheet-like waterproofing laminates are applied to structures at temperatures below about 40.degree. F. Included in this invention are improved, pre-formed, flexible sheet-like waterproofing laminates which are applicable to various buildings and other civil engineering structures at temperatures below 40.degree. F.
2. Description of Related Art
Various materials used in building construction and other civil engineering projects such as roads, bridges, buildings, foundations, and plaza decks are susceptible to water penetration resulting, in part, from their inherent properties. Reducing or eliminating water penetration through structures formed of these materials often is desirable and may be critical in certain structures such as those housing sensitive electronic equipment or tunnels moving vehicular or pedestrian traffic under bodies of water. For many year, flexible, sheet-like waterproofing laminates of support films and bituminous layers pre-formed in a factory have been employed as waterproofing agents.
Although pre-formed, flexible sheet-like waterproofing laminates of support films and bituminous layers have been used for many years, use of these laminates continues to be limited by the widely recognized but unmet need for laminates which can be applied confidently at cold temperatures. Thus, when ambient temperatures fall below about 40.degree. F., particularly below 25.degree. F., application of waterproofing laminates generally is abandoned and replaced by hot applied waterproofing agents. Weak lap adhesion, i.e., laminate to laminate adhesion at joints between laminate sections, is the primary factor restricting low temperature application. Even specialized laminates recommended for application at temperatures below 40.degree. F. are not applied at temperatures below 25.degree. F. because of weak lap adhesion.
Flexible, pre-formed laminates of the type mentioned above and their use to form waterproofing layers in various kinds of building structures are described in, for example, U.S. Pat. Nos. 3,741,856; 3,583,682; and 3,900,102 to Hurst. U.S. Pat. No. 4,172,830 to Rosenberg et al. is another of many examples disclosing sheet-like flexible materials used for waterproofing.
Currently there are available waterproofing laminates recommended for application down to 25.degree. F. These products include a polyethylene layer and a bituminous layer including asphalt, process oil, rubber, and filler.
U.S. Pat. No. 4,755,545 to Lalwani describes a self-sealing roofing adhesive blend including 50-95% by weight of a bituminous component, 4-40% by weight of an inert filler, and 1-6% by weight of a thermoplastic block polymer of styrene and butadiene monomers.
U.S. Pat. No. 4,547,399 to Fujihara et al. discloses a composition effective for sealing cracks and joints in asphalt and concrete streets and highways that includes paving grade asphalt, process oil (not over 32%), and styrene-butadiene rubber or rubbers.
U.S. Pat. Nos. 4,328,147 and 4,382,989 to Chang et al. describe asphaltic compositions useful as roofing asphalts which include 39-99% by weight of oxidized asphalt and from 1-8% oxidized polyethylene.
U.S. Pat. No. 4,459,157 to Koons describes a composition of an asphalt blend in which a butadiene-styrene elastomeric block copolymer is dispersed and contains 5-45% by weight of catalytic petroleum cracker bottoms oil. This composition is characterized further by a low asphaltene content.